Emergency typo fix

Author: adam-urbanczyk

cadquery/occ_impl/shapes.py

@@ -805,7 +805,7 @@ def computeMass(obj: "Shape", tol: Optional[float] = None) -> float:
         Properties = GProp_GProps()
         calc_function = Shape._mass_calc_function(obj)
 
-        calc_function(obj.wrapped, Properties, *(tol if tol else ()))
+        calc_function(obj.wrapped, Properties, *((tol,) if tol else ()))
 
         return Properties.Mass()